/usr/lib/x86_64-linux-gnu/libphonon4qt5.so is in libphonon4qt5-dev 4:4.8.3-0ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libphonon4qt5.so.4
/usr/lib/x86_64-linux-gnu/libphonon4qt5.so.4